#define _GNU_SOURCE
#include <sched.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <semaphore.h>
#include <unistd.h>
#include <string.h>

char buffer[8][4];
int bp = 0;
pthread_mutex_t mutex;
sem_t product;
sem_t warehouse;

int producer(void *arg) {
    int id = *((int *)arg);
    //printf("i am the producer process, my processid is %d, my id is %d\n", getpid(),id);
    int i;
    for(i = 0;i<10;i++) {
        sleep(i+1); // 体现线程速度差别
        sem_wait(&warehouse);
        pthread_mutex_lock(&mutex);
        if (id == 0) {
            strcpy(buffer[bp],"aaa\0");
        }else{
            strcpy(buffer[bp],"bbb\0");
        }
        bp++;
        printf("producer %d produce %s in %d\n",id,buffer[bp-1],bp-1);


        pthread_mutex_unlock(&mutex);
        sem_post(&product);
    }
    printf("producer %d is over!\n",id);
}

int consumer(void *arg) {
    int id = *((int *)arg);
    //printf("i am the consumer process, my processid is %d, my id is %d\n", getpid(),id);
    int i;
    for(i = 0;i<10;i++) {
        sleep(10-i); // 体现线程速度差别
        sem_wait(&product);
        pthread_mutex_lock(&mutex);

        bp--;
        printf("consumer %d get %s in %d\n",id,buffer[bp],bp);
        strcpy(buffer[bp],"zzz\0");

        pthread_mutex_unlock(&mutex);
        sem_post(&warehouse);
    }
    printf("consumer %d is over!\n",id);
}

int main() {
    pthread_mutex_init(&mutex,NULL);//初始化
    sem_init(&product,0,0);
    sem_init(&warehouse,0,8);
    int clone_flag,arg,retval;
    char *stack;
    clone_flag = CLONE_VM|CLONE_SIGHAND|CLONE_FS|CLONE_FILES;
    int i;
    for(i = 0;i<2;i++){/*创建4个线程*/
        arg = i;
        stack = (char*)malloc(4096);
        retval = clone((void *)producer,&(stack[4095]),clone_flag,( void * )&arg);
        stack = (char*)malloc(4096);
        retval = clone((void *)consumer,&(stack[4095]),clone_flag,( void * )&arg);
        usleep(1);/*这里不能用sleep，usleep和sleep的区别在于它们的参数单位不同。sleep的参数是秒数，而usleep的参数是微秒数。*/
    }
}